In December 1724, Catharina married a much older Samuel Coeymans at the Albany Dutch church. The marriage produced no children as her husband was in his fifties at the time of the marriage.

In January 1737, she was among the heirs named to share in the extensive estate of her father.

The couple lived for most of their marriage on the "Coeymans Patent" in the substantial riverside home they shared with Samuel's married but also childless sister.

Samuel Coeymans died in 1754 leaving his wife well-provided for in his will.

Widow Catharina may have lived in Albany itself as the widow identified on a census of householders made by the British army in 1756. However, her extensive holdings in south Albany stood out on the 1760s tax rolls as well.

Catharina Van Schaick Coeymans filed a will in September 1763. Following the path set by her husband a decade earlier, her estate went to Ten Eyck and Van Schaick kin. The will passed probate in June 1771.